STEEL STRIP HAVING HIGH STRENGTH AND HIGH FORMABILITY, THE STEEL STRIP HAVING A HOT DIP ZINC BASED COATING.

摘要

The invention relates to a steel strip having a hot dip zinc based coating, the steel strip having the following composition, in weight%,: C: 0.17 - 0.24 Mn:. 1.8 - 2.5 Si: 0.65 - 1.25 Al: ≤ 0.3 optionally: Nb: ≤ 0.1 and/or V: ≤ 0.3 and/or Ti: ≤ 0.15 and/or Cr: ≤ 0.5 and/or Mo: ≤ 0.3, the remainder being iron and unavoidable impurities, with a Si/Mn ratio ≤ 0.5 and a Si/C ratio ≥ 3.0, with an Mn equivalent ME of at most 3.5, wherein ME = Mn + Cr + 2 Mo (in wt.%) having a microstructure with (in vol.%): ferrite: 0 - 40 bainite: 20 - 70 martensite: 7 - 30 retained austenite: 5 - 20 pearlite: ≤ 2 cementite: ≤ 1 having a tensile strength in the range of 960 - 1100 MPa, a yield strength of at least 500 MPa, and a uniform elongation of at least 12%.